The present invention relates to a composition and method for lubricating an internal combustion engine, providing improved fuel economy and retention of fuel economy.
Fuel economy is of great importance, and lubricants which can foster improved fuel economy, by, for instance, leading to reduced friction within an engine, are of significant value. The present invention provides a lubricant composition, including an additive package, which leads to improved fuel economy in an internal combustion engine. This improvement is effected by providing an additive package in which the detergent component is exclusively or predominantly an alkylsulfonate.
U.S. Pat. No. 4,952,328, Davis et al., Aug. 28, 2990, discloses lubricating oil compositions for internal combustion engines, comprising (A) oil of lubricating viscosity, (B) a carboxylic derivative produced by reacting a succinic acylating agent with certain amines, and (C) a basic alkali metal salt of sulfonic or carboxylic acid. An illustrative lubricant composition (Lubricant III) includes base oil including viscosity index modifier; a basic magnesium alkylated benzene sulfonate; an overbased sodium alkylbenzene sulfonate; a basic calcium alkylated benzene sulfonate; succinimide dispersant; and zinc salts of a phosphorodithioic acids.
U.S. Pat. No. 4,326,972, Chamberlin, Apr. 27, 1982, discloses lubricant compositions for improving fuel economy of internal combustion engines. The composition includes a specific sulfurized composition (based on an ester of a carboxylic acid) and a basic alkali metal sulfonate. Additional ingredients may include at least one oil-dispersible detergent or dispersant, a viscosity improving agent, and a specific salt of a phosphorus acid.
U.S. Pat. No. 3,994,815, Coleman, Nov. 30, 1976, discloses lubricating compositions. Disclosed in an example is an additive concentrate prepared using a polyisobutylene synthetic lubricating oil containing a hydrogenated butadiene-styrene copolymer; a dispersant; a zinc isobutylamyl phosphorodithioate, an overbased calcium sulfonate detergent, and an anti-foaming agent.